ASoC: msm: Do not set volume to zero during session open

Setting stream volume to 0 will cause problem when user
starts playback from aplay. The previous volume which is
set gets overwritten with 0 when the playback starts. To
avoid this user space can control the volume setting at
the start of the playback.

Change-Id: I3776bb7ffd390ff0cfb56462bebb60a9163a7796
Signed-off-by: Phani Kumar Uppalapati <phaniu@codeaurora.org>